The present invention relates generally to communications systems, and more particularly, to a system allowing frequency reuse with existing systems in a non-blocking manner.
In this communication age, content providers are increasingly investigating ways in which to provide more content to users as well as interfacing with users.
Communication satellites have become commonplace for use in many types of communication services, e.g., data transfer, voice communications, television spot beam coverage, and other data transfer applications. As such, satellites transmit and receive large amounts of signals used in either a xe2x80x9cbent pipexe2x80x9d or xe2x80x9cspot arrayxe2x80x9d configuration to transmit signals to desired geographic locations on the earth.
Because the frequency of resources are scarce for over-the-air transmission, various encoding schemes are used to provide a greater number of communication signals within an allocated communication band spectrum. Such encoding schemes include code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), or combination of these schemes. Further, to prevent interference the schemes may operate at various frequencies.
There is a continual need to provide new systems. However, if no spectrum is available typically potential system operators must forgo a pursuing a system. Typically, the same spectrum can not be assigned to different systems because of the potential for interference of the communications signals.
It would therefore be desirable to provide a system that allows reuse of frequency spectrums allocated to other systems in a non-blocking manner.
It is therefore one object of the invention to provide an improved communications system that allows frequency reuse in a manner which prevents interference with existing systems.
In one aspect of the invention, a method for operating a communication system comprises the steps of:
defining a service area having a blocking area therein, said blocking area having a separation angle between a first position of the satellite and a second position of the stratospheric platform less than a predetermined angle;
generating a first beam using a first frequency directed at the service area with the satellite; and
generating a second beam using the first frequency directed at the service area outside the blocking area from the stratospheric platform.
In a further aspect of the invention, a communications system includes a high altitude communication device that communicates with a plurality of user terminals and a gateway station. The gateway station couples the users to terrestrial networks and other users. The high altitude communication device has a controller that generates a second beam having the first frequency to a service area. The stratospheric platform does not generate the second beam within a blocking area. User terminals within the service area and outside the blocking area are configured to receive the first beam and the second beam.
One advantage of the invention is that the user terminals for existing systems may be reused. Another advantage of the system is that several users platforms reusing the as frequency spectrum may be employed within the system.